Atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) is a worldwide-used herbicide and often detected in agricultural soils and groundwater at concentrations above the permitted limit, because of its high mobility, persistence, and massive application. This study applied pot experiments to investigate the atrazine contents and speciation during the phytoremediation process by Pennisetum alopecuroides (L.) Spreng. in laterite soils. From the change of the total atrazine and bioavailable atrazine measured by diffusive gradients in thin film (DGT), P. alopecuroides significantly improved atrazine degradation efficiency from 15.22 to 51.46%, attributing to the increasing bioavailable atrazine in rhizosphere. Only a small amount of atrazine was taken up by P. alopecuroides root and the acropetal translocation from roots to shoots was limited. The atrazine speciation was significantly different between rhizosphere and non-rhizosphere, attributing to the declining pH and organic matters in rhizosphere. The relationship between pH and soil-bound/humus-fixed atrazine illustrated the pH-dependant release of the atrazine from soils and the competition between humus adsorption and uptake by P. alopecuroides. The present study reveals the important roles of soil pH and organic matters in atrazine speciation and availability in laterite soils, and provides new insights in the rhizospheric effects on effective phytoremediation of atrazine.

Phosphate-solubilizing fungi (PSF) can secrete large amounts of organic acids. In this study, the application of the fungus Penicillium oxalicum and geological fluorapatite (FAp) to lead immobilization was investigated. The formation and morphology of the lead-related minerals were analyzed by ATR-IR, XRD, Raman, and SEM. The quantity of organic acids secreted by P. oxalicum reached the maximum on the fourth day, which elevated soluble P concentrations from 0.4 to 108 mg/L in water. The secreted oxalic acid dominates the acidity in solution. P. oxalicum can survive in the solution with Pb concentration of ~ 1700 mg/L. In addition, it was shown that ~ 98% lead cations were removed while the fungus was cultured with Pb (~ 1700 mg/L) and FAp. The mechanism is that the released P from FAp (enhanced by organic acids) can react with Pb²⁺ to form the stable pyromorphite mineral [Pb₅(PO₄)₃F]. The precipitation of lead oxalate also contributes to Pb immobilization. However, lead oxalate is more soluble due to its relatively high solubility. P. oxalicum has a higher rate of organic acid secretion compared with other typical PSF, e.g., Aspergillus niger. This study sheds light on bright future of applying P. oxalicum in Pb remediation.

In the northwest of Iran, the dust of salty and toxic metals possibly caused due to drying Urmia Lake is threatening the health of surrounding communities. This study aimed to employ leaves of local deciduous trees for biomonitoring of toxic elements and to evaluate air pollution tolerance of the trees for greenbelt application. Sampling from leaves of four dominant tree species including Vitis vinifera, Juglans regia, Ulmus umbraculifera, and Popolus alba was carried out from gardens in two radial distances (5 and 10 km) around the Urmia Lake accounting for 16 sites. The concentration of metals in the leaves were extracted according to method USEPA method 3050B and measured by ICP AES technique. According to the levels of air pollution tolerance index (APTI), Popolus alba showed to be more sensitive to air pollution and can be applied for biomonitoring. The ranks of heavy metals and sodium concentrations in the leaves gained in the order of Na > Zn > Cu > Ni > Pb > As > Cd. The mean enrichment factor for the elements was calculated from 1 to 3, suggesting minor enrichment for them. As, Pb, and Na with similar spatial distribution were dominantly observed in northwest and center-east of the Urmia Lake. Potential ecological risk (PER) index showed a moderate risk in 6% of sampling zones, where Cd and As were identified as responsible pollutants. Principle component and correlation analysis between the elements depicted human sources such as industrial activity and road traffic for Cd, Cu, Ni, Pb, and Zn, whereas As and Na were most likely originated from the aerosols of Urmia Lake. Our findings showed that Popolus alba can be applied as a local biomonitor and Vitis vinifera with moderate tolerance can be used as a good air pollutant sink in greenbelt development around the drying Urmia Lake in the northwest of Iran.

Imidacloprid (IM) is a neonicotinoid insecticide, used in a wide range of agricultural activities worldwide. However, it results in ecosystem disturbances and signs of toxicity in human and animals. The current study was designed to elucidate the protective effects of omega-3-fatty acids (OFAs) and vitamin E (Vit E) against IM hepatotoxicity in Japanese quails. Seventy male quails (30 days old) were divided into seven groups (n = 10); G₁ −ve control; G₂ received IM (+ve control); G₃ received OFA; G₄ received Vit E; and G₅, G₆, and G₇ received OFA and/or Vit E with IM for 30 days, respectively. Blood and liver tissue samples were collected. Imidacloprid significantly (p < 0.05) increased serum levels of alanine transferase (ALT), aspartate transferase (AST), triglycerides (TGC), and low-density lipoprotein cholesterol (LDL-C), as well as liver tissue malondialdehyde (MDA) concentration. Moreover, IM caused a significant (p < 0.05) decrease in the levels of serum high-density lipoprotein cholesterol (HDL-C), as well as liver superoxide dismutase (SOD) enzyme activity and reduced-glutathione (GSH) concentration in comparison to the –ve control group. Histopathological changes in hepatocytes, including thick cell trabeculae with marked hydropic vacuolar degeneration of cytoplasm, were found in IM-treated group. Treatment with OFA and/or Vit E resulted in significant improvements in general body condition, serum HDL-C level, and liver tissue SOD enzyme activity and GSH concentration, as well as significant decreases in the levels of serum AST, ALT, TGC, LDL-C, and hepatic tissue MDA. In conclusion, OFA and Vit E have a protective effect against IM toxicity, especially in their combination.

Ag/Bi₂WO₆/graphene oxide composite with excellent photocatalytic properties was successfully prepared by hydrothermal-photoreduction synergistic method and is applied in antibiotics degradation. The structure and properties of as-prepared photocatalysts were characterized by Fourier infrared spectrum (FTIR), X-ray photoelectron spectroscopy (XPS), specific surface area analyzer (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), and atomic force microscope (AFM). The results indicated that Ag and Bi₂WO₆ were uniformly loaded on the surface of graphene oxide. In addition, graphene oxide with conjugated carbon network structures has been applied as a photocatalyst supporter for the high electronic conductivity and the large reactive sites. Compared with the pure graphene oxide, the as-prepared Ag/Bi₂WO₆/graphene oxide catalyst exhibited excellent degradation efficiency and stability for degrading tylosin under Xe lamp irradiation. Under simulated sunlight irradiation, the photodegradation efficiency of tylosin by Ag/Bi₂WO₆/graphene oxide achieved at 98% within 2 h, compared to 50% by pure graphene oxide. The excellent photodegradation ability is caused by the synergetic effect of Ag, Bi₂WO₆, and graphene oxide nanoparticles.

In Bamenda and peripheral zones, studies have been focused on the effects of pesticides on farmers (pesticide users) while nothing has been done to assess the exposure of sellers to pesticides. This study aimed at evaluating the exposure of pesticide sellers in the same area. Thirty-two questionnaires were administered to 32 pesticide sellers systematically selected, and chi-square was used for statistical analysis. From each shop, a respondent was chosen among the workers according to its daily time spent in the workplace. The results showed that there is similarity between sellers in Bamenda and peripheral area; one active ingredient (metalaxyl) and one formulation (beauchamp) sold are not registered; throat irritation, headaches, fatigue, skin irritation, eye irritation, and difficulty in breathing with more cases of nose irritation were symptoms observed; pesticides are stored either in the shops or in warehouses; safety measures generally applied are sitting outside the shop, taking medicated charcoal and the use of protective clothing; 56% have less than 5 years experience. Permanent pesticide sellers are then exposed to chronic intoxication in Bamenda and neighboring zones. Employers should make use of protective clothing in their shops when manipulating pesticides in the application of safety measures.

This paper aims to analyse the characteristics and properties of the fractions obtained from slow pyrolysis of non-edible seed cake of Calophyllum inophyllum (CI). The gas, bio-oil and biochar obtained from the pyrolysis carried out at 500 °C in a fixed bed batch type reactor at a heating rate of 30 °C/min were characterized by various analytical techniques. Owing to the high volatile content of CI biomass (72.61%), it was selected as the raw material in this present investigation. GC-MS and FT-IR analysis of bio-oil showed the presence of higher amount of oxygenated compounds, phenol derivatives, esters, acid and furans. The physicochemical properties of the bio-oil were tested as per ASTM norms which imply that bio-oil is a highly viscous liquid with lower heating value as compared to that of diesel fuel. The chemical composition of evolved gas was analysed by using GC testing which revealed the presence of combustible components. The FT-IR characterization of biochar showed the presence of aliphatic and aromatic hydrocarbons whereas the elevated amount of carbon in biochar indicates its potential to be used as solid fuel. The performance and emission characteristics of CI engine were assessed with different CI bio-oil blends and compared with baseline diesel fuel. The results showed that addition of bio-oil leads to decreased brake thermal efficiency and increased brake specific energy consumption. Meanwhile, increase in blend ratio reduces harmful pollutants such as oxides of nitrogen and smoke in the exhaust. From the engine testing, it is suggested to employ 20% of CI bio-oil blends in CI engine to obtain better operation.

BTEX (benzene, toluene, ethylbenzene, xylene) and formaldehyde are toxic compounds that can induce adverse health effect in humans. This study measured in-home and ambient concentrations of BTEX and formaldehyde across Tehran, Iran. These pollutants were sampled from the indoor and adjacent outdoor air of 45 houses (9 in each city zone) during the winter of 2015. Sampling was repeated three times for each house. The analyses were performed according to NIOSH procedures. The effect of flooring material, wall covering, ventilation system, heating system, height above ground, presence of attached garages, and distance from highways was evaluated. In addition, carcinogenic and non-carcinogenic risks of these compounds were assessed. The average indoor concentrations of benzene, toluene, ethylbenzene, xylene, and formaldehyde were 53.2, 21.5, 14.4, 21.1, and 17.9 μg/m³, respectively. The average outdoor concentrations of benzene, toluene, ethylbenzene, xylene, and formaldehyde were 43.5, 26.2, 10.0, 19.1, and 6.9 μg/m³, respectively. Separate regression models showed that wall coating, ventilation system, heating system, flat level, and distance from highways explained 29, 60, 16, 60, and 59% of the BTEX concentrations, respectively. Houses with oil painted walls and parquet flooring had higher concentrations of BTEX and formaldehyde, respectively. The health risk assessment found that the carcinogenic risks of benzene and formaldehyde exceeded 1 × 10⁻⁴ and represent a definite risk. New buildings can be designed based on the results of this study to use better materials and optimum building designs to reduce exposure to these toxic air pollutants.